Switching lever mechanism

ABSTRACT

A switching lever mechanism for operating a switching lever between two end positions comprising first and second laterally spaced apart cams, a follower lever physically mounted between its ends and including one end with a roller follower disposed between the cams. An opposite end of the follower lever is connectible to a member for shifting the member. A socket is formed on the follower lever between the roller follower and the pivotal mounting thereof and a bolt having a spherical head is pivotally mounted on the socket. A bracket mounted in a stationary position alongside the follower lever is provided with a set screw having a head portion. A sleeve is pivotally mounted on the head portion and carries the bolt. A spring biases the sleeve and bolt outwardly to hold the follower lever in either of its two end positions.

This is a division of application Ser. No. 824,697 filed Aug. 15, 1977,now U.S. Pat. No. 4,159,924.

FIELD AND BACKGROUND OF THE INVENTION

This invention relates in general to coke ovens and, in particular, to anew and useful device for automatically and periodically switching theregenerative heating system of coke oven batteries from one group ofheating flues to another, comprising a switchgear equipped with camcylinders, cam levers, and valves, and using a pressurized or hydraulicfluid, such as oil, for driving working cylinders by which gas and aircocks, valves and other shutoff mechanisms are actuated, and which isalso equipped with pressure fluid reservoirs and pressure pumps, andfurther relates to a device for converting the heating of the batteryfrom one kind of gas to another.

DESCRIPTION OF THE PRIOR ART

A switching device for a regeneratively heated, vertical flued coke ovenbattery is known, from German Pat. No. 1,188,553, in which the cocks,valves, etc., of the individual heating walls are actuated, in acontrolled manner, by hydraulically operated working cylinders, with oneworking cylinder being mounted at each oven side for each kind of cock,valve, etc., which are to be switched in groups by a common linkage orthe like. A centrally controlled actuation by the operating fluid of theworking cylinder is provided for opening the gas cocks of the one ovenside, through a pressure reservoir.

A counterweight provides the return motion of the de-pressurized workingcylinder and the closing of the gas cocks at the same side with theoperating fluid flowing back to a reservoir. To open the waste-heatvalves at one oven side and to close the air flaps at one oven side, acommon working cylinder is provided, which is also centrally controlledand pressure-fluid operated. The depressurized return motion is assistedby a counterweight with the operating fluid flowing back into thereservoir and it is utilized for closing of the heat valves and openingof the air flaps. Further, electrical contact mechanisms are provided onthe linkage of the working cylinders, which are connected to lockingrelays in the central control and serve the purpose of ensuring thecorrect order of switching.

Three-way cocks are provided in each of the pressure-fluid lines leadingfrom the control device to the working cylinders of the gas cocks. Thegas cocks are controlled by the pressure of the oven heating gas and aremounted in a manner such that, with a decrease of the gas pressure, theoperating fluid conduits for the gas cocks held open, and extendingbetween the control device and the working cylinders, are closed; andthe conduits for the fluid flowing from the working cylinders to theoutlet are opened, whereby, the return motions for the cylinders arestarted.

Further, according to a particular design disclosed in German Pat. No.1,236,465, at both the pusher side and the coke side, a pump forsupplying the pressurized operating fluid to the various cylindersmounted on both sides, as well as a common oil reservoir for the twopumps are provided.

This equipment has proven satisfactory in service and it performs, forexample, with a bisected heating of the batteries, the followingoperations:

A. at the burn-up side;

1. closes the heating gas cocks

2. closes the air flaps

3. opens the waste-heat valves

Then, after scavenging with air for about 15 seconds,

B. at the burn-off side;

4. opens the air flaps

5. closes the waste-heat valves

6. opens the heating gas cocks.

In embodiments of the prior art, the switchgears are put into operationby means of two cam cylinders, whose cams control roller carrying camlevers which, in turn, are connected to valves for adjusting theoperating position thereof. If, however, two cam cylinders are disposedside-by-side or one above the other, the device becomes difficult tosurvey and inaccessible for repairs, particularly on the two camcylinders.

SUMMARY OF THE INVENTION

The present invention is directed to a control device for coke ovenoperation which is simple in design, more suitable for inspection,readily accessible for repairs and more resistant to wear. In accordancewith the invention, instead of providing two cylinders as hithertofore,the control device is equipped with a single cam cylinder and therollers of the cam levers do not move against the outer surfaces of thecams, as in the prior art, but engage the lateral surfaces thereof. Byomitting the second cam cylinder, the inventive device becomes easy tosurvey and accessible for repairs. Repair work required, however, isreduced to a considerable extent.

In a particular embodiment of the invention, the automatic device forconverting the operation from one kind of heating gas to another thus,for example, from lean gas to strong gas, or vice versa, is similarlydesigned, i.e., with only a single cam cylinder also. In this design, inaccordance with the invention, the cam cylinder for converting the modeof operation from one heating gas to another is axially aligned and, bymeans of a coupling mechanism, is rendered engageable with the camcylinder for periodical switching, and is mounted for movement by thedrive of the cam cylinder. To this end, the cam cylinder to be coupledis moved in the direction of its longitudinal axis. If, in such anarrangement, the cam levers were to follow the front faces of the cams,the cams had to be beveled and the rollers of the cam levers shapedconically, in order to obtain a switching motion of the cam levers upona longitudinal displacement of the cam cylinder. A sliding engagement ofsuch conical rollers with beveled cams causes considerable wear of therollers. On the contrary, by providing a lateral engagement of the camlever rollers on the lateral cam surfaces, even with a longitudinaldisplacement of the cam cylinder, no particular design of the cams androllers, for example, beveling and conical shape, is necessary, andneither cams nor rollers are exposed to any significant wear.

During conversion of the heating from strong gas to lean gas and viceversa, the following operations are performed:

1. Closing of the inlet cocks for the non-selected kind of gas on eachheating wall;

2. opening of the inlet cocks for the selected kind of gas on eachheating wall;

3. To heat with lean gas, closing of the air flaps of theregenerator-chamber waste gas valves, which are used in such operationfor preheating the gas;

To heat with strong gas, they must be actuated in a predeterminedrhythm;

4. While converting from strong gas to lean gas, enlarging of the airinlets in the conversion valves of the regenerator chambers, throughwhich air is admitted both during strong gas and lean gas heating, to anapproximately double area, and inversely, for well-known reasons;

5. For heating with lean gas, where the waste gas valves of theregenerator chambers serve for gas preheating, closing and opening ofthese valves in the same direction as the lean gas switching coks. Forstrong gas heating, however, they must be switched in the same directionas the waste gas valves; and

6. Adjustment of the stack draft, which differs depending on the type ofgas used.

A device which automatically performs these operations is disclosed, forexample, in German Pat. No. 1,961,579. By uniting such a device with thedevice for periodically switching the heating, in accordance with theinvention, an important simplification of the entire heating mechanismof coke-oven batteries is obtained.

In accordance with a further development of the invention, forsimplifying the construction and improving its inspection, all valves,i.e., both those for switching the heating and those for converting themode of gas operation, are united to well-known valve blocks, and forreasons of manufacture and assembly, three blocks are provided.Accordingly, an object of the invention is to provide a combined controldevice for the operation of coke-oven batteries which includes both acontrol part for converting from heating from a strong gas to a leangas, and inversely, and a control part for switching the regenerativeheating system from one group of heating flues to another.

Another object of the invention is to provide a combined control devicefor operation of coke-oven batteries, both for switching purposes andfor converting from one heating gas to another, which includes a rotaryswitching control cylinder which is rotatably mounted on a support framealongside of a rotary conversion control cylinder in a manner such thatthey may be rotated together or only one may be rotated, and whichincludes a plurality of axially spaced, circumferentially arranged camson each cylinder providing controls for the operation of switchingvalves which are arranged alongside each cylinder and which operate therespective converting valve elements and switching valve elementsassociated with the respective cylinders.

A further object of the invention is to provide an improved camconstruction for operating control valves of a switching or convertingoperation of a coke oven.

Another object of the invention is to provide a control device and valveconstruction which are simple in design, rugged in construction andeconomical to manufacture.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this disclosure. For a better understanding of the invention,its operating advantages and specific objects attained by its uses,reference should be had to the accompanying drawings and descriptivematter in which there is illustrated a combined device for switching andconverting.

BRIEF DESCRIPTION OF THE DRAWINGS

In the Drawings:

FIG. 1 is a side elevational view of a switching control device for theoperation of a coke oven, constructed in accordance with the invention;

FIG. 2 is a top plan view of the device;

FIG. 3 is a partial sectional view taken along the line 3--3 of FIG. 1;

FIG. 4 is an enlarged partial sectional view of a rotary controlcylinder or conversion cylinder indicating the connection of the controlcams thereto;

FIG. 5 is an enlarged partial elevational view showing a portion of acontrol cylinder and a portion of the valve operating control lever foroperating the switching operation;

FIGS. 6 and 7 are views, similar to FIG. 5, showing advanced stages ofoperation of the lever;

FIG. 8 is a partial view, similar to FIG. 5, showing a portion of theconversion cylinder and the associated control lever for operating theconversion valves; and

FIG. 9 is a view similar to FIG. 8 showing an opposite end position ofthe conversion control lever.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings in particular, the invention embodied therein,comprises a combined control device for the operation of a coke ovenbattery which is shown in FIGS. 1 and 2, and which includes a controlpart in the form of a cylinder 11, which is mounted for rotation about ahorizontal axis and is employed for the control of the switching of theregenerative heating system from one group of heating flues to anotherand which is arranged alongside of another control part or cylinder 12which is provided for control of the conversion from a heating from astrong gas to a lean gas, or vice versa.

In accordance with the invention, the control is effected by theselected rotation of the switching cylinder 11 alone or by the combinedrotation of the switching cylinder 12 which may be engaged with cylinder11 and the operation is effected by actuating one or more control valves14 for switching which are arranged in spaced axial location alongsidethe associated switching cylinder or by actuating one or more of thecontrol valves 14a for effecting the conversion which are arranged inspaced axial location along the conversion cylinder 12.

The device includes a base frame 10 on which the rotary control cylinder11 and the rotary control cylinder 12 are arranged alongside of threevalve blocks 13a, 13b, 13c, control valves 14 and 14a, and controllevers 15 and 15a.

The two rotary cylinders 11 and 12 are equipped with a drive comprisinga hydraulic motor 16 and a gear transmission 17 by which the speed ofthe motor is reduced to the desired cylinder speed. In case of failureof drives 16 and 17 or of other troubles, cylinders 11 and 12 may alsobe rotated manually. For this purpose, a handwheel 18 is provided.Handwheel 18 is keyed on a shaft 19 which is supported at two points. Agear 20 is secured to the opposite end of shaft 19, which meshes with agear 21 mounted on control cylinder 11. It is advisable to disengage amultiple disc clutch 22 which is provided between control cylinder 11and worm gear 17 prior to rotating the cylinders manually, in order tonegate the braking effect of drive motor 16 and gear 17. Theinstantaneous position of cylinders 11 and 12 is transmitted, through achain drive 23, to a pointer 24 and can be read on a dial 25. A returnstop 26 allows rotation in only one direction.

Control cylinder 11 and conversion cylinder 12 are received inpillow-block bearings 27, 28 and 29 (FIG. 2). Conversion cylinder 12 ismounted so as to be displaceable in the direction of its longitudinalaxis by a definite stroke, for performing an additional switchingmotion. The movement of the stroke is effected by a cylinder 30 which isconnected to the conversion cylinder 12 through a special bearingconstruction 31. This bearing construction prevents a piston rod 31a ofcylinder 30 from rotating along with cylinder 12. Cylinder 30 isoperated by a pressurized fluid which is supplied through a valve (notshown) which is completely independent of the rest of the device.

The displacement of conversion cylinder 12 in the direction of itslongitudinal axis requires, in addition, a particular common bearingarrangement with control cylinder 11. This arrangement comprises a pin32 (FIG. 2) carried by conversion cylinder 12, which is introduced in abore 33 of control cylinder 11, whereupon the rotary motion of controlcylinder 11 is transmitted, through sliding feather keys or splines 34,to conversion cylinder 12. Consequently, control cylinder 11 andconversion cylinder 12 always rotate in the same direction, whichcomplies with the intended function of the device.

Control cylinder 11 and conversion cylinder 12 are equipped with cams36, 37 and 45. FIG. 4 shows how the cams 36 and 37 are secured to thecylinders. Cylinders 11 and 12 are provided with grooves 35 into whichcams 36, 37, 45 (FIGS. 8 and 9) are inserted. Upon tightening therespective screws, shims 38 and screws 39 press the cams into grooves 35and thus prevent cams 36, 37, 45 from falling out or being displaced. Atthe same time, however, this manner of securing makes it possible todisplace the cams along the circumference of the cylinder into anydesired position. For reasons of mounting, and in order to be able toadjust the endpoints of the cams on the circumference of the cylinderexactly, the cams are split.

The cams actuate control levers 15, 15a (See FIGS. 2, 3, 5 and 8)Control levers 15, 15a are pivotally mounted on base frame 10, by meansof a bolt 40, intermediate their ends. The lower ends of levers 15, 15aare provided with longitudinal slots or bores into which sliding blocks41 are inserted. Sliding blocks 41 have cross-bores into which valvelevers 42 of control valves 14, 14a are engaged. The reason for thisdesign is that valve levers 42 of control valves 14, 14a move in a planewhich is perpendicular to the plane of motion of control levers 15, 15a.

The upper end of control levers 15, 15a is equipped with bolts 43 androtary rollers 44. Rollers 44 run on the lateral surfaces 36a, 37a, 45aof the cams. The actuation of a control lever 15 of control cylinder 11by cams 36, 37 secured to the circumference of the cylinder isillustrated in FIGS. 5, 6 and 7:

(a) As shown in FIG. 5, control lever 15 is swung out to the righthandside, about its pivot 40, and its roller 44 applies against cam 36. Thecam is split midway of its ends and each end is beveled.

(b) The control cylinder rotates in the direction indicated by arrows inFIG. 6. This moves cam 36 upwardly and the next cam 37 comes intoengagement. Roller 44 of control lever 15 comes into contact with theinclined surface of cam 37 and is thereby pushed to the lefthand side.

(c) In FIG. 7, control lever 15 is in its extreme lefthand end positionin which it runs on cam 37.

The two end positions of the control levers are predetermined by therespective cam and the stop in the associated control valve 14. This isthe case only at control cylinder 11, however, since this cylinder isequipped with cams along its entire circumference, while conversioncylinder 12 is equipped with only short cam pieces 45 (see FIG. 8). Forthis reason, control levers 15a of conversion cylinder 12 are providedwith special holding mechanisms, generally designated 46a. Thesemechanisms retain control lever 15a and, thereby, also valve lever 42,firmly in their swung-out end positions.

Each of the mentioned mechanisms 46a (see FIG. 8), comprises a sleeve46, a bank of cup springs 47, and a bolt 48 having a spherical end 49which end is seated in a ball socket 50 of control lever 15a. The bankof cup springs 47 is biased by means of a set screw 51 and check nut 52.Set screw 51, which is inserted in a bracket 53, has a spherical head 54which is movably seated in sleeve 46. The spring force actingeccentrically of the point of rotation holds control lever 15a firmly inits end position. For pivoting the control lever into its other endposition, it is necessary to first overcome the torque produced by theeccentrically acting spring force, up to the mid-position of controllever 15a. Control lever 15a is then pivoted into this other endposition by the spring force.

The two end positions of the control levers are predetermined by stops55 provided on control levers 15a and by adjustable buffers 56. Thebuffers 56 are inserted in brackets 53. Brackets 53 are secured to baseframe 10 by screws 57.

Control levers 15 and 15a actuate control valves 14 and 14a throughvalve levers 42. All of the control valves 14 and 14a are secured tovalve blocks 13a, 13b and 13c by means of screws 59 (FIGS. 1, 2 and 3).All of the control valves 14, 14a are conventional valves for base platemounting (i.e., the valves are screwed to a flat plate to which the pipeconduits for the hydraulic equipment are connected) and the base platesare designed, in accordance with the invention, as valve blocks 13a, 13band 13c. On their upper side, valve blocks 13a, 13b, 13c exhibit thesame pattern of holes as the control valves. O-rings 60 (FIG. 3)provides a sealing between the communicating bores of control valves 14,14a and of the valve blocks. In this way, the exchange of defectivevalves is substantially facilitated since no pipes are to be screwed onor off.

Valves blocks 13a, 13b, 13c are provided with a plurality oflongitudinal and cross-bores 61 in their interior, see FIG. 3. Thesebores convey pressurized fluid to or from the individual control valves14, 14a, depending on the switching position of the valves, and alsoconnect the individual valves to one another. The underside of the valveblock is provided with tapholes to which, the individual pipes 63leading to the hydraulic equipment are connected by means of screwedjoints 62.

For reasons of ease in the drilling operation, valve blocks 13a, 13b and13c are assembled of three individual blocks and two head plates 64a and64b, and are held in an assembled state by four tie rods 65 (FIGS. 1 and2). Each individual longitudinal bore 61 is sealed by O-rings in theparting planes. Pressure and return connections 66, 66a are provided inhead plates 64a, 64b.

Valve blocks 13a, 13b and 13c are supported on set screws 67 permittingan accurate vertical adjustment. For adjustment in the horizontal plane,screws 68 are provided on each end of the assembled valve blocks. Screws68 are inserted in brackets 69 which are welded to base frame 10.

Base frame 10 is a steel structure supported on the floor by means offour legs 70. In the lower part of the base frame, drip pans 71 areprovided in which operating fluid is collected in case fo failures.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:
 1. A switching lever mechanism for operating aswitching lever between two end positions, comprising first and secondlaterally spaced apart cams, a follower lever pivotally mounted betweenits ends and including one end with a roller follower disposed betweensaid cams, and an opposite end connectable to a member for shifting themember, a socket formed on said follower lever between the rollerfollower and the pivotal mounting thereof, a bolt having a sphericalhead pivotally mounted in said socket, a bracket mounted in a stationaryposition alongside said follower lever and having a set screw with ahead portion, a sleeve pivotally mounted on said head portion andcarrying said bolt, and spring means in said sleeve biasing said boltoutwardly, said sleeve being pivoted centrally between said cams so thatwhen said follower lever is engaged in one end position, it will bebiased by said spring into that end position, and when it moves beyonddead center or the pivotal location of the mounting of said sleeve, itwill switch over and bias the lever into an opposite end positionagainst the other of the cams.